Work machines which utilize a track type drive mechanism have several advantages over wheel type work machines. For instance, the tracks give the work machine excellent traction by spreading the weight of the machine over a large area. Thus, the track type work machine has enhanced off road capabilities.
A typical undercarriage of a track type drive mechanism consists of a track having of a number of shoes linked together, a sprocket which drives the track, and a number of rollers which distribute the weight of the work machine along the track.
The shoes include a drive lug, and a number of links. The drive lugs engage the drive sprocket in order to advance the track. The links pivotably couple each shoe to the adjacent shoes so as to allow the track to advance in along an oval path.
Certain track configurations support the weight of the work machine on the number of links. In particular, the number of rollers are rotatably supported by the links during advancement of the track. A disadvantage to such a configuration is that the stress of advancing the track around the work machine and the stress of supporting the weight of the work machine are combined which may decrease the useful life of the number of links.
A further disadvantage to such a configuration is that the various wear surfaces of each of the links cannot be replaced independently of each other. In some abrasive environments, such as environments which include sand, the upper surface of the links which is in contact with the rollers are subjected wear at a greater rate than the surfaces of the links which pivotably couple the links together. Thus, it is likely that wear on the upper surface would require the entire link to be replaced even though the surfaces that pivotably couple the links together still possess significant useful life.
What is needed therefore is an apparatus and method for driving a track type work machine which overcomes one or more of the above-mentioned drawbacks.